1. Field of the Invention
The present invention relates to a touch panel detecting the position on the display face of a detection target such as a finger and a pen and a display unit including the touch panel.
2. Description of the Related Art
In the past, a technology of detecting the position where a detection target such as a finger and a pen is contacted with the display face of a display unit has been known. Specially, examples of representative and generally prevailing technologies include a display unit including a touch panel. There are various types of touch panels. Examples of generally prevailing touch panels include a resistive touch panel. In the resistive touch panel, the panel surface has, for example, a laminated structure in which an extremely small spacer is sandwiched between a glass and a film opposed to each other. For the glass and the film, a transparent electrode grating is provided on each face opposed to each other. When a finger or a pen is contacted with the surface of the film, the film is bent, the transparent electrode of the film face and the transparent electrode of the glass face are contacted with each other, and a current is flown. Thus, by measuring a voltage dividing ratio due to resistance of the respective transparent electrodes of the glass face and the film face, the position of the finger or the pen is detected. Therefore, by using such a touch panel, a user is able to intuitively operate the display unit.
FIG. 9 is a perspective view illustrating a schematic configuration of the foregoing resistive touch panel. FIG. 10 is an exploded view of the touch panel of FIG. 9. The touch panel includes, for example, a pair of an upper substrate 110 and a lower substrate 120 arranged oppositely with a certain gap in between. Between the pair of the upper substrate 110 and the lower substrate 120, a flexible printed circuit board (FPC) 130 and an adhesion layer 140 are provided.
The upper substrate 110 has a transparent substrate 111 as a contact face 110A to be contacted with a finger, a pen or the like. On the opposite face (lower face) of the contact face 110A of the transparent substrate 111, a resistive film 112 is provided. Around the resistive film 112 of the lower face of the transparent substrate 111, strip-shaped wiring layers 113A and 113B that are linked to and electrically connected to the resistive film 112 are provided. Each of one end of the wiring layers 113A and 113B is provided in a region opposed to an end portion 130A of the FPC 130, and is contacted with an electrode (not illustrated) of the FPC 130.
The lower substrate 120 has a transparent substrate 121 that supports a resistive film 122 (described later) with which the resistive film 112 is to be contacted when the finger, the pen or the like is contacted with the upper substrate 110. The foregoing resistive film 122 is provided on a face (upper face) opposed to the upper substrate 110 in the transparent substrate 121 and in a region opposed to the resistive film 112. Around the resistive film 122 of the upper face of the transparent substrate 121, strip-shaped wiring layers 123A and 123B that are linked to the resistive film 122 are provided. Each of one end of the wiring layers 123A and 123B is provided in a region opposed to the end portion 130A of the FPC 130, and is contacted with the electrode of the FPC 130.
The adhesion layer 140 is in the shape of a ring having an aperture 140A in a region opposed to the resistive film 112, and is arranged between the wiring layers 113A and 113B on the transparent substrate 111 and the wiring layers 123A and 123B on the transparent substrate 121. Thereby, the adhesion layer 140 insulates the wiring layers 113A and 113B from the wiring layers 123A and 123B, and adheres the upper substrate 110 and the lower substrate 120. The adhesion layer 140 has a notch 140B in a region opposed to the PFC 130, and is not overlapped with the FPC 130 viewed from the thickness direction. The adhesion layer 140 is made of, for example, a double-faced tape.
For a general configuration of the resistive touch panel, for example, a description is also given in Japanese Unexamined Patent Application Publication No. 2002-182854 and the like.